Endoluminal medical procedures are now common in many countries as they can significantly reduce clinical procedure times, can effect localised treatments, and can significantly reduce patient trauma and convalescence. Many techniques, including the well-established Seldinger procedure, make use of a guide wire which is fed from a remote percutaneous entry point through the patient's vasculature to the site to be treated. The treatment could be in a major vessel, such as the aorta or vena cava, but increasingly may be within a very small and delicate vessels such as the cerebral vessels.
Generally, the guide wire is the first element of an introducer assembly which is positioned at the treatment site, with the other elements of the introducer assembly subsequently being fed over the guide wire from the same percutaneous entry point. For this purpose, it is important that the guide wire is sufficiently soft, particularly at its distal end, in order to be able to curve through the patient's vasculature and into and through any branch vessels. However, it is also important for the guide wire to exhibit some strength, or rigidity, so that it can effectively guide the subsequently deployed elements of the introducer assembly through the tortuous paths of the patient's vasculature. Often, this leads to the guide wire having to exhibit contradictory characteristics of softness and strength. In some circumstances, such as in neurological applications, it is not possible or optimal to compromise on softness and strength, with the result that it becomes necessary to use in the same procedure a plurality of guide wires having different characteristics.